Injuries have kept Lauri Markkanen and John Collins shelved to start their sophomore seasons. As rookies, however, both looked like long-term starters for their respective teams.

The Chicago Bulls will be tougher to defend following the return of Markkanen, who'll improve spacing and give the lineup another high-level scorer alongside Zach LaVine.

The 7-footer averaged 15.2 points and 2.1 threes last year, wowing with unique shooting range, face-up ball skill and coordination for a player his size.

Collins averaged 19.0 points during summer league in July, appearing sharper offensively with his shooting and execution inside the arc. He's in line for a higher-usage role upon his return, and he'll benefit from the addition of Trae Young, with whom Collins will pair well in the pick-and-roll and drive-and-dump games.

10. Josh Hart, Los Angeles Lakers

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The final pick in last year's first round, Josh Hart has emerged as a key rotation player for the Los Angeles Lakers.

He's making 2.1 threes per game and converting 46.7 percent of his catch-and-shoot opportunities.

He'll be a tougher cover in the half court when his pull-up game (30.0 percent) starts to improve. But the Lakers value Hart's consistent shooting and defense, and it's helped him pass Kentavious Caldwell-Pope on the depth chart.

9. Dennis Smith, Dallas Mavericks

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Averaging 16.5 points, Dennis Smith Jr. looks similar to last year, scoring off his explosiveness, ball-handling and shot-making. The addition of Luka Doncic has limited his playmaking, though, an area of Smith's game that needed improvement.

He's totaled just 30 assists to 27 turnovers through eight games. The most noticeable improvement so far has been with his pull-up, which he's converting at a 41.0 percent clip, up from last year's 29.1 percent mark.

Smith applies pressure with his ability to blow by or stop and pop from anywhere. Eventually, though, to take the next step developmentally, he'll need to start maturing as a lead guard in terms of using his dribble and touches more efficiently.

8. Zach Collins, Portland Trail Blazers

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Even with Jusuf Nurkic, the Portland Trail Blazers have had to play Zach Collins, who's clearly made strides.

Shooting 59.0 percent, he's averaging 10.8 points and 1.8 blocks in just 20.9 minutes. Collins looks quick off the ground, posing as a high-percentage target around the basket, as well as an active, mobile rim protector.

Skill-wise, he's flashed post moves and shooting ability (8-of-19 3PT) that hint at a future inside-out big the Blazers can feature offensively. It's still all about long-term potential with Collins, but he's secured a spot in the rotation now at 20 years old.

7. Jarrett Allen, Brooklyn Nets

He's shooting 60.3 percent and blocking 1.9 shots a game, tapping into his length and mobility for easy finishes and rim protection.

Allen hasn't found a shooting rhythm yet or established a post presence as a scorer. He's still an every-game weapon around the basket just by playing to his physical strengths. Only three players are averaging more points per game on pick-and-rolls.

Baby steps are acceptable for the 20-year-old. The next big one should be working toward becoming a routine catch-and-shoot threat.

6. Lonzo Ball, Los Angeles Lakers

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Matt York/Associated Press

The additions of LeBron James and Rajon Rondo have taken away playmaking chances for Lonzo Ball, whose time of possession (2.5 minutes) has been cut in half from a year ago (5.2 minutes). He's gone from averaging 7.2 assists to 4.3. But Ball has played closer to his strengths as a scorer, and it's led to improved efficiency, with the sophomore shooting significantly better inside the arc (50.0 percent) and behind it (39.5 percent).

He's getting more open looks off the ball, where he's knocking down 40.0 percent of his catch-and-shoots. And he's had success finishing around the trees, converting 59.1 percent of his attempts within 10 feet.

His passing and defensive IQ remain constants that allow Ball to add value, even during games when he isn't scoring. He won't blow up statistically in year No. 2, but he also won't need to for his impact to be felt.

5. Kyle Kuzma, Los Angeles Lakers

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Even with the additions of LeBron James, Lance Stephenson, Rajon Rondo and JaVale McGee, Kyle Kuzma is scoring more than last year, when he averaged 16.1 points.

He's the No. 2 option behind James, putting in 18.4 points a game despite not shooting (30.0 percent 3PT) as well as he could be.

Punishing defenses from each level with soft hands and coordination around the basket (62.9 percent inside 10 feet) and face-up body control and post moves in the mid-range—plus a three-ball that's falling 1.7 times a game—Kuzma is back with his balanced scoring and versatility.

4. De'Aaron Fox, Sacramento Kings

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The early front-runner to make the biggest rookie-to-sophomore leap, De'Aaron Fox has led the Sacramento Kings to a 6-3 start, averaging 19.0 points and 7.8 assists.

Thursday night's 31-point, 15-assist, 10-rebound triple-double looked like a statement. Fox is a different player, more decisive driving to the basket and shooting off the dribble.

He's being used in 8.4 pick-and-rolls per game, top 10 in the league and up from 6.2 a year ago. And after ranking last in pace last season, Sacramento now ranks No. 2, per ESPN.com, playing to Fox's speed and ability to create easier looks in transition.

As a scorer, he's knocking down 2.6 pull-ups per game at a 40.4 percent clip. He hit three triples against Atlanta. His perimeter game is slowly coming around, as is his overall point guard leadership in running the show and making decisions.

Fox has been highly convincing to the point where he's now looking like the favorite to emerge as the No. 1 point guard from the 2017 class.

3. Jayson Tatum, Boston Celtics

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With the Boston Celtics at full strength, they're overflowing with scorers and forwards. And it's been tougher for Jayson Tatum to find a rhythm.

He's still averaging 15.8 points per game, showcasing the same footwork and shot-making ability that appeared to fuel All-Star scoring potential a year ago. Tatum has quickly emerged as Boston's No. 2 option, taking more shots per game than Marcus Morris, Al Horford, Gordon Hayward and Jaylen Brown.

A portion of those attempts are also lower-percentage looks, with Tatum averaging 5.1 mid-range jumpers a game, up from 2.7. He's settling for contested specialty shots a little too often.

He'll pick up his 41.2 percent field-goal mark as the season progresses. Tatum figures to eventually start drilling more of his pull-ups and spot-ups. But a slower start keeps him from passing either of last year's Rookie of the Year finalists on the ladder early in season No. 2.

2. Donovan Mitchell, Utah Jazz

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Donovan Mitchell has picked up where he left off as a rookie, torching defenses with potent scoring ability fueled by explosive athleticism, special ball-handling and difficult shot-making.

He's already had a signature performance, having erupted for 38 points in a win over the Houston Rockets.

Mitchell has been deadlier shooting off the dribble, making 2.6 pull-ups at a 38.9 percent clip, up from 35.3 percent in his rookie season.

The fact he's only converting 50.6 percent inside 10 feet, after making 62.0 percent of those attempts a year ago, suggests that Mitchell's 22.4 points per game could rise even further as the season progresses.

1. Ben Simmons, Philadelphia 76ers

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Ben Simmons still looks like the sophomore class' most impactful player.

His scoring efficiency is down early (47.4 percent FG), though the nine-game sample size is small and he's had to adjust with Markelle Fultz, another ball-handler, joining the rotation for 24.1 minutes a game.

Per 36 minutes, Simmons' rebounding (10.5) and assist rates (9.3) are up from 8.7 and 8.7 as a rookie. And he's scoring at close to the same rate as last year (15.4 points per 36, down from 16.9).

Attention will start shifting toward the development of his jump shot, which he's used sparingly. But he's also looked relatively competent on the shorter attempts, resulting in Brett Brown encouraging Simmons to shoot more of them.